克服低C2+收益在酸性CO2电还原:调节局部疏水性提高性能
Small (Weinheim an der Bergstrasse, Germany)
|December 10, 2023
概括
改变催化剂的疏水性可以显著提高酸性介质中的电化学二氧化碳减排 (CO2RR). 这种方法抑制了的演变,提高了CO2RR效率和多碳产品产量,用于稳定的工业应用.
科学领域:
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
背景情况:
- 在酸性介质中的电化学二氧化碳减排 (CO2RR) 提供了诸如稳定的电解质循环等优势.
- 然而,演化反应 (HER) 和低多碳 (C2+) 产品产量阻碍了在酸中有效的CO2RR.
- 控制催化剂的局部环境是克服这些挑战的关键.
研究的目的:
- 调查局部疏水性对酸性CO2RR性能的影响.
- 开发一种调整催化剂疏水性的简单方法.
- 为了提高CO2RR效率,对C2+产品的选择性,以及在酸性介质中的运行稳定性.
主要方法:
- 直接电位被用来微调催化剂层的疏水性,没有添加剂.
- 在酸性介质 (pH=2) 中评估了电化学性能.
- 在工业相关的电流密度下进行了长期稳定性测试.
主要成果:
- 一个高度疏水的微环境显著抑制了HER,并改善了CO2RR的性能.
- 对于C2+产品的法拉戴效率 (FE) 在疏水环境中的电沉积铜上达到74%左右.
- 该方法证明了可扩展性,在CO2RR中达到~81%的总FE,在C2+物种中达到~62%的FE.
- 在300 mA cm-2下实现了超过50小时的稳定运行.
结论:
- 界面的疏水性在增强酸性CO2RR中起着至关重要的作用.
- 开发的方法很容易,普遍适用,并且有效地通过CO2RR在酸性介质中生产高价值产品.
- 这种方法为高效和稳定的工业二氧化碳转化提供了一个有希望的途径.
更多相关视频
相关概念视频
Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
2.9K
Hydrolysis of esters under acidic conditions proceeds through a nucleophilic acyl substitution. In the presence of excess water, the reaction proceeds in a reversible manner, forming carboxylic acids and alcohols.
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...
2.9K
Carbocations
11.3K
Carbocations are one of the reaction intermediates formed during several nucleophilic substitutions or elimination reactions. A carbocation is an electron-deficient species with the central carbon atom having six electrons and three bonded atoms. The central carbon in a carbocation is sp2 hybridized with trigonal planar geometry. It has an empty p orbital perpendicular to the plane of the structure that can accept electrons. Thus, carbocations act as strong electrophiles and may react with any...
11.3K
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
8.4K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
8.4K
Acid Halides to Carboxylic Acids: Hydrolysis
2.7K
Hydrolysis of acid halides is a nucleophilic acyl substitution reaction in which acid halides react with water to give carboxylic acids. The reaction occurs readily and does not require acid or a base catalyst.
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic...
2.7K
Leveling Effect
810
In acid-base chemistry, the leveling effect refers to the limitation imposed by the solvent on the strength of acids and bases in solution. When a base stronger than the solvent's conjugate base is used, it deprotonates the solvent until the base is entirely consumed, making it ineffective against weaker acids. Conversely, an acid stronger than the solvent's conjugate acid protonates the solvent until the acid is depleted, rendering it ineffective against weaker bases. Essentially, the...
810
Substituent Effects on Acidity of Carboxylic Acids
6.7K
The acidity of carboxylic acids is influenced by the nature of the substituents bounded to the functional group. The acid strength is determined by the stability of the carboxylate anion—the conjugate base formed by dissociating the corresponding carboxylic acid.
6.7K


